DNR News

June 20, 2012

DNR initiates grassland habitat restoration projects

Native grassland ecosystems have decreased considerably across the Southeast in the last century. In particular, longleaf pine savannas and woodlands with grassland understories have diminished significantly in range since European settlement.

The S.C. Department of Natural Resources (DNR) is very fortunate to own several Wildlife Management Areas (WMA) that offer opportunities for ecological restoration projects. More specifically, approximately 12,000 acres of upland habitat on Woodbury (Marion Co.), Marsh (Marion Co.), and McBee (Chesterfield Co.) WMA's are actively managed for grassland restoration.

So far, DNR has thinned (selective removal of trees) several hundred acres of pine timber on all three properties. The open forest canopy, resulting from these thinning operations, allows more light to reach the ground, thereby improving conditions for understory plant growth. In these thinned areas DNR staff has begun systematic application of prescribed fire. DNR plans to expand these management activities into additional stands as they mature. Positive results are already evident as native warm season grasses and forbs (an herb other than grass) have become more prevalent in the managed stands.

Pine savanna habitat is characterized by a relatively open forest canopy (generally longleaf pine) with an understory of native warm season grasses and forbs. Hundreds of plants grow only in this forest type and many wildlife species are specially adapted to this ecosystem. One recognizable species associated with pine savanna habitat is the red-cockaded woodpecker. Another notable grassland species, especially important to many sportsmen, is the northern bobwhite quail. Both the red –cockaded woodpecker and quail require the herbaceous (non woody plants) understory characteristic of open pine savannas to provide food and cover.

Grasslands also provide habitat for many reptiles, songbirds, and other game animals such as fox squirrels, eastern wild turkey, and white-tailed deer. In the Southeast, the lack of early successional (an understory dominated by colonizing herbaceous vegetation) grassland habitat has been the most significant factor contributing to the decline of northern bobwhite and other grassland bird species.

Disturbance is necessary to retain the grass and forb plant component in pine savanna habitat. In most cases, prescribed fire is the most efficient and beneficial method to maintain early successional habitat.

By controlling the frequency, intensity, pattern, and season of prescribed burning, forest managers can manipulate vegetation to promote a variety of outcomes to benefit wildlife. The use of prescribed fire can alter plant species occurring in a forest and affect the structural diversity of those species. Frequent fire generally promotes the growth of herbaceous vegetation by stimulating sprouting of grasses and forbs and by reducing hardwood encroachment.

The longleaf pine savanna habitat once covered approximately 90 million acres across the southeastern coastal plain region. This forest type was maintained by frequent fire propagated by native people and by lightning strike ignition. Native Americans and early European and African settlers recognized the benefits of maintaining fire in these forest systems for both themselves and wildlife.

During the late 19th and early 20th centuries, a growing demand for wood products and naval stores, coupled with the suppression of fire, resulted in the loss of millions of acres of the longleaf pine ecosystem. Additionally, the conversion of pine savanna to other forest types, agriculture and development further reduced native grasslands. Currently, pine savanna covers less than three percent of its historic range.